diff --git a/modules/openapi-generator/src/main/resources/rust/hyper/api.mustache b/modules/openapi-generator/src/main/resources/rust/hyper/api.mustache
index ad0410bc9e4..9c0f7fd314b 100644
--- a/modules/openapi-generator/src/main/resources/rust/hyper/api.mustache
+++ b/modules/openapi-generator/src/main/resources/rust/hyper/api.mustache
@@ -74,7 +74,15 @@ impl<C: Connect>{{{classname}}} for {{{classname}}}Client<C>
         {{/required}}
         {{^required}}
         if let Some(ref s) = {{{paramName}}} {
-            let query_value = {{#isArray}}s.iter().map(|s| s.to_string()).collect::<Vec<String>>().join(","){{/isArray}}{{^isArray}}s.to_string(){{/isArray}};
+            {{#isArray}}
+            let query_value = s.iter().map(|s| s.to_string()).collect::<Vec<String>>().join(",");
+            {{/isArray}}
+            {{^isArray}}
+            let query_value = match serde_json::to_string(s) {
+                Ok(value) => value,
+                Err(e) => return Box::pin(futures::future::err(Error::Serde(e))),
+            };
+            {{/isArray}}
             req = req.with_query_param("{{{baseName}}}".to_string(), query_value);
         }
         {{/required}}
diff --git a/modules/openapi-generator/src/main/resources/rust/hyper0x/api.mustache b/modules/openapi-generator/src/main/resources/rust/hyper0x/api.mustache
index f59705ea7b7..fe1a65c7920 100644
--- a/modules/openapi-generator/src/main/resources/rust/hyper0x/api.mustache
+++ b/modules/openapi-generator/src/main/resources/rust/hyper0x/api.mustache
@@ -73,7 +73,15 @@ impl<C: hyper::client::connect::Connect>{{{classname}}} for {{{classname}}}Clien
         {{/required}}
         {{^required}}
         if let Some(ref s) = {{{paramName}}} {
-            let query_value = {{#isArray}}s.iter().map(|s| s.to_string()).collect::<Vec<String>>().join(","){{/isArray}}{{^isArray}}s.to_string(){{/isArray}};
+            {{#isArray}}
+            let query_value = s.iter().map(|s| s.to_string()).collect::<Vec<String>>().join(",");
+            {{/isArray}}
+            {{^isArray}}
+            let query_value = match serde_json::to_string(s) {
+                Ok(value) => value,
+                Err(e) => return Box::pin(futures::future::err(Error::Serde(e))),
+            };
+            {{/isArray}}
             req = req.with_query_param("{{{baseName}}}".to_string(), query_value);
         }
         {{/required}}
diff --git a/samples/client/petstore/rust/hyper/petstore/src/apis/fake_api.rs b/samples/client/petstore/rust/hyper/petstore/src/apis/fake_api.rs
index 8e422ef9d4b..8247b1b21de 100644
--- a/samples/client/petstore/rust/hyper/petstore/src/apis/fake_api.rs
+++ b/samples/client/petstore/rust/hyper/petstore/src/apis/fake_api.rs
@@ -47,7 +47,10 @@ impl<C: Connect>FakeApi for FakeApiClient<C>
         let mut req = __internal_request::Request::new(hyper::Method::GET, "/fake/user/{user_name}".to_string())
         ;
         if let Some(ref s) = content {
-            let query_value = s.to_string();
+            let query_value = match serde_json::to_string(s) {
+                Ok(value) => value,
+                Err(e) => return Box::pin(futures::future::err(Error::Serde(e))),
+            };
             req = req.with_query_param("content".to_string(), query_value);
         }
         req = req.with_query_param("anyType".to_string(), any_type.to_string());
diff --git a/samples/client/petstore/rust/hyper/petstore/src/apis/pet_api.rs b/samples/client/petstore/rust/hyper/petstore/src/apis/pet_api.rs
index f6c8e0f0d83..d66d351e01a 100644
--- a/samples/client/petstore/rust/hyper/petstore/src/apis/pet_api.rs
+++ b/samples/client/petstore/rust/hyper/petstore/src/apis/pet_api.rs
@@ -118,7 +118,10 @@ impl<C: Connect>PetApi for PetApiClient<C>
         let mut req = __internal_request::Request::new(hyper::Method::POST, "/pets/explode".to_string())
         ;
         if let Some(ref s) = page_explode {
-            let query_value = s.to_string();
+            let query_value = match serde_json::to_string(s) {
+                Ok(value) => value,
+                Err(e) => return Box::pin(futures::future::err(Error::Serde(e))),
+            };
             req = req.with_query_param("pageExplode".to_string(), query_value);
         }
 
@@ -130,7 +133,10 @@ impl<C: Connect>PetApi for PetApiClient<C>
         let mut req = __internal_request::Request::new(hyper::Method::POST, "/pets".to_string())
         ;
         if let Some(ref s) = page {
-            let query_value = s.to_string();
+            let query_value = match serde_json::to_string(s) {
+                Ok(value) => value,
+                Err(e) => return Box::pin(futures::future::err(Error::Serde(e))),
+            };
             req = req.with_query_param("page".to_string(), query_value);
         }
 
diff --git a/samples/client/petstore/rust/hyper0x/petstore/src/apis/fake_api.rs b/samples/client/petstore/rust/hyper0x/petstore/src/apis/fake_api.rs
index 099602bb22a..fb74cf88997 100644
--- a/samples/client/petstore/rust/hyper0x/petstore/src/apis/fake_api.rs
+++ b/samples/client/petstore/rust/hyper0x/petstore/src/apis/fake_api.rs
@@ -46,7 +46,10 @@ impl<C: hyper::client::connect::Connect>FakeApi for FakeApiClient<C>
         let mut req = __internal_request::Request::new(hyper::Method::GET, "/fake/user/{user_name}".to_string())
         ;
         if let Some(ref s) = content {
-            let query_value = s.to_string();
+            let query_value = match serde_json::to_string(s) {
+                Ok(value) => value,
+                Err(e) => return Box::pin(futures::future::err(Error::Serde(e))),
+            };
             req = req.with_query_param("content".to_string(), query_value);
         }
         req = req.with_query_param("anyType".to_string(), any_type.to_string());
diff --git a/samples/client/petstore/rust/hyper0x/petstore/src/apis/pet_api.rs b/samples/client/petstore/rust/hyper0x/petstore/src/apis/pet_api.rs
index dac261755a9..8c2f35c7ead 100644
--- a/samples/client/petstore/rust/hyper0x/petstore/src/apis/pet_api.rs
+++ b/samples/client/petstore/rust/hyper0x/petstore/src/apis/pet_api.rs
@@ -117,7 +117,10 @@ impl<C: hyper::client::connect::Connect>PetApi for PetApiClient<C>
         let mut req = __internal_request::Request::new(hyper::Method::POST, "/pets/explode".to_string())
         ;
         if let Some(ref s) = page_explode {
-            let query_value = s.to_string();
+            let query_value = match serde_json::to_string(s) {
+                Ok(value) => value,
+                Err(e) => return Box::pin(futures::future::err(Error::Serde(e))),
+            };
             req = req.with_query_param("pageExplode".to_string(), query_value);
         }
 
@@ -129,7 +132,10 @@ impl<C: hyper::client::connect::Connect>PetApi for PetApiClient<C>
         let mut req = __internal_request::Request::new(hyper::Method::POST, "/pets".to_string())
         ;
         if let Some(ref s) = page {
-            let query_value = s.to_string();
+            let query_value = match serde_json::to_string(s) {
+                Ok(value) => value,
+                Err(e) => return Box::pin(futures::future::err(Error::Serde(e))),
+            };
             req = req.with_query_param("page".to_string(), query_value);
         }